If a step in a stage fails, you will need to create a new snapshot if a new version of a project is required to resolve the issue. However, there may be cases where the resolution does not require a new snapshot, and it is undesirable to start over at the beginning of the pipeline. In such cases you can replay the failed snapshot in the stage. When replaying a snapshot, the stage starts at the very beginning. That is, at the first gate, or at the first step if there are no gates.
To replay a failed stage, click on the replay stage 
icon within the header of the target stage.
